Various sports, such as baseball, involve the danger of injury by impact such as from a thrown or batted ball. This danger is particularly acute in little league play where fatalities have resulted from arrhythmia when the batter is struck by a pitched ball in the general area of the heart. One of the theories explaining the reason for the fatalities is that impact of the ball against the pulmonary sac occurs when the heart is between beats.
Although the fatalities occurring in little league play has received much publicity, the same danger is attendant for other types of sports. For example, impact from a field hockey stick could also result in fatalities as well as impact from any sport of activity involving high speed projectiles or a relatively great force being struck by any object such as a stick or club or bat during the participation of a sport or other activity.